Greetings and happy holidays to all of you folks!
I was trying to install WINXP from one of the back-up copies I have (the original one is misplaced). The problem is the pc in which I am installing it does not "see" this cd when placed in the cd rom. I thought that maybe the disc was bad so I tried it in another pc and it can read it fine. I just then connected the regular hard disk to the pc that does not see the disc loaded the operating system I normally used in that pc which is WIN 2000 and the pc "sees" the disc. So I know the disc is OK I know the CD drive is OK.My question is why the cd is not seeing when trying to install it to a clean hard drive?. Last time I remember that no matter what I did I was not able to install the OS from the copy cd but I was lucky enough to find the original one , it seems now I have run out of luck.........(because the wife cleaned the "chaotic area" around my pc and you all know what happens when wife cleans........:D ) Thank you for all your help

It maybe because the CD format may not be recognised by the CD ROM.
These cases do happen with DVD drives but it maybe just the case with your CD rom too . Is the CD rom an old make?

There is a common problem whereby burned CDR and CDRW (especially if they were not orinally closed) cannot be read by CD-drives whereas retail, pressed CDROMs can be. You will thus need to use the original pressed CDROM or, even temporarily, use a drive that can see the CDR/RW or possibly close an unclosed CDR/RW with Nero or similar (may or may not be possible or successful) on another PC with a burner.

The alternative is to copy the i386 folder to the hard drive (http://paulski.com/zpages.php?id=1711) (via a network or usb pen drive etc) and then run <path>\i386\winnt.exe instead of the normal setup.exe from DOS running from a boot floppy or CD.

There is a common problem whereby burned CDR and CDRW (especially if they were not orinally closed) cannot be read by CD-drives whereas retail, pressed CDROMs can be. You will thus need to use the original pressed CDROM or, even temporarily, use a drive that can see the CDR/RW or possibly close an unclosed CDR/RW with Nero or similar (may or may not be possible or successful) on another PC with a burner.

The alternative is to copy the i386 folder to the hard drive (http://paulski.com/zpages.php?id=1711) (via a network or usb pen drive etc) and then run <path>\i386\winnt.exe instead of the normal setup.exe from DOS running from a boot floppy or CD.

The thing that puzzles me is that when I used that same pc and thatsame cd rom drive but with a hard drive with the OS already installed then the disc can be read.

The thing that puzzles me is that when I used that same pc and thatsame cd rom drive but with a hard drive with the OS already installed then the disc can be read.
I suppose its possible there is no boot sector on the copied CD. If it was copied by just copying the files across it wont be bootable. To make an exact clone (which thereby includes the boot sector) the correct software needs to be used or an iso used as an intermediary. You can check if it has a boot sector with isobuster.

Try seeing if you can see this CD from a DOS boot floppy with CDROM support. If you can then you can run winnt.exe directly from the CD that way without copying the files to the hard drive.

I suppose its possible there is no boot sector on the copied CD. If it was copied by just copying the files across it wont be bootable. To make an exact clone (which thereby includes the boot sector) the correct software needs to be used or an iso used as an intermediary. You can check if it has a boot sector with isobuster.

Try seeing if you can see this CD from a DOS boot floppy with CDROM support. If you can then you can run winnt.exe directly from the CD that way without copying the files to the hard drive.

I think the cd is bootable because as soon as I load it into the cd rom of a pc with a working hard drive the cd goes into setup asking if I want to upgrade the OS.

the cd goes into setup asking if I want to upgradeNope. That is nothing to do with bootability. That is just autorun, which only works from within Windows. Try isobuster (http://www.isobuster.com/isobusterdownload.php) or tell us exactly how you made the copy. However there's nothing wrong with starting the install from within windows - just choose new installation and not upgrade.